The World Trade Center (WTC) was a complex of seven buildings in Lower Manhattan in New York City that were destroyed in the September 11, 2001, terrorist attacks. The site is currently being rebuilt with six new skyscrapers and a memorial to the casualties of the attacks. At the time of its completion, it was the tallest building in the world, surpassing the Empire State Building which was also built in Manhattan. With the construction of 7 World Trade Center in the 1980s, the World Trade Center had a total of seven buildings, but the most notable were the main two towers, which each were 110 stories tall, stood over 1,350 feet (410 m) high, and occupied about one acre (43,560 square feet) of the total 16 acres (65,000 m2) of the site's land. During the 1990s, approximately 500 companies had offices in the complex. The Windows on the World restaurant was located on the 106th and 107th floors of 1 World Trade Center (the North Tower) while the Top of the World observation deck was located on the 107th floor of 2 World Trade Center (the South Tower). Minoru Yamasaki was the main architect.